1. Field of the Invention
The present invention relates to an image copying device.
2. Description of Related Art
A conventional image copying device is provided with an automatic document feeder (ADF) for automatically supplying documents to an image reading device, such as a charge-coupled device (CCD) or contact image sensor (CIS), in order to read in a plurality of documents sequentially. The image copying device produces copy products of the thus-read-in documents, by forming the read-in images on a recording medium by using an image forming device such as an inkjet type recording device or a laser type recording device.
The ADF is generally provided with no document-reversing mechanism. It is necessary for the operator to turn over the pages when copying documents with images formed on both surfaces thereof. In order to copy a plurality of documents with images formed on both sides thereof, the documents are sequentially supplied by the ADF so that the images on the first surfaces (the surfaces of the documents that are read in first, such as the front surfaces) are read in first by a CCD sensor or the like. Thereafter, the images on the other sides of the documents (the surfaces of the documents that are read in after, such as the rear surfaces) are read in in the same manner as described above. Then, images are formed based on the read-in image data.
In this way, the images on the front surfaces of the documents are read in first, and then the images on the rear surfaces of the documents are read in. This manner reduces the work of re-inserting the documents and is more convenient for the operator, in comparison with a conceivable method in which both surfaces of the first document are read in first, both surfaces of the next document are read in next, and both surfaces of the subsequent documents are read in in the same manner as described above.
According to Japanese Unexamined Patent Application Publication No. 7-131601, image data for the front surfaces of all the read-in documents and image data for the rear surfaces of all the read-in documents are stored in a storage device such as RAM. The image data for the front surface of each document is linked to the image data for the rear surface of the same document. A pair of sets of image data that are linked in this manner for each document are formed on a pair of opposite surfaces of a single recording medium, thereby producing a copy product of the subject document.